The present invention relates to articles of feminine hygiene known as tampons, and more particularly to improvements in so-called digital tampons which are insertable directly by hand and, as a rule, are provided with strings serving to facilitate manual extraction of tampons from body cavities.
A digital tampon normally resembles an elongated bullet-shaped cylinder having a rounded leading end and a trailing end or another part attached to one end of a string the other end of which is accessible at the exterior of the inlet to the body cavity which receives the tampon. Each tampon is confined in a tubular envelope which is or which can be made of a light-transmitting material and is closed at both ends. An intermediate portion of the envelope is or can be provided with a tear strip which facilitates access to the tampon preparatory to introduction into a body cavity. The string is stored in the envelope in folded condition adjacent the trailing end of the tampon.
Attempts to facilitate predictable folding of strings at the trailing ends of the tampons prior to closing of both ends of the respective tubular envelopes include the introduction of tampons and of the respective strings into tubular carriers and circulation of air in the carriers for the purpose of influencing the folding of the strings, i.e., the ultimate shape and positioning of the string within the confines of a closed tubular envelope at the trailing end of the respective tampon. The utilization of currents of air contributes significantly to the complexity and cost of heretofore known apparatus which are designed to confine tampons and their strings in tubular envelopes. Moreover, the utilization of air currents does not ensure predictable folding of the strings; as a rule, the folded portions of a string extend randomly in part across and in part along short arcuate paths at the trailing ends of the respective tampons.
Another drawback of heretofore known methods of and apparatus for confining digital tampons in tubular envelopes is that the configuration of the closed ends of tubular envelopes at the trailing ends of the confined tampons varies from tampon to tampon. Such closing is effected by devices which fold the respective still open ends of the tubes not unlike the flaps of envelopes so that the thus obtained closed ends include a plurality of partially overlapping panels intended to be disposed in planes which are normal to the longitudinal axes of the respective tampons. Neighboring panels define relatively sharp corner portions or "ears" which are apt to scratch the hand of the person desiring to remove the tubular envelope from a confined tampon and its string.
Still another drawback of heretofore known methods of and apparatus for confining digital tampons in tubular envelopes is that the closed ends of the envelopes at the trailing ends of the confined tampons are not adequately sealed. As a rule, such sealing is effected by advancing the closed ends of envelopes at the trailing ends of the confined tampons along a heated surface which is supposed to establish a bond between the overlapping or partially overlapping panels at the respective closed ends of the envelopes. Such treatment does not ensure reliable bonding of the partially or fully overlapping panels to each other. In addition, the advancement of tubular envelopes along a heated surface is likely to intensify the formation of the aforediscussed undesirable corner portions or "ears".
An additional drawback of conventional methods of and apparatus for confining digital tampons in tubular envelopes is that the desirable recesses at the trailing ends of the tampons are likely to disappear or that their depth is reduced and/or that their shape is altered during storage of confined tampons. Such recesses are desirable for convenient application of the tip of an index finger or another finger during introduction of an unsealed tampon into a body cavity. The aforediscussed advancement of closed ends of tubular envelopes adjacent the trailing ends of confined tampons is likely to contribute to a reduction of the depth of recesses in the trailing ends of the tampons. Furthermore, the condensed material of a confined tampon tends to expand in the interior of its envelope. A finished envelope does not or is not likely to yield in a radial direction; however, it does not interfere with an expansion of the tampon in a direction to reduce the depth of the recess in its trailing end.
Last but not least, tampons which are confined in tubular envelopes exhibiting some or all of the aforediscussed drawbacks and/or defects cannot be readily collated and introduced into cartons or other receptacles for arrays consisting of selected numbers of confined tampons. In addition, the lack of uniformity of closed ends of tubular envelopes adjacent the trailing ends of the confined tampons detracts from the appearance of such products.